Push switch

ABSTRACT

A push switch ( 1 ) includes an internal button ( 40 ), an external button ( 10 ), a switch ( 30 ) disposed inside the internal button ( 40 ), a casing ( 50 ) fixed to a side wall ( 43 ) of the internal button ( 40 ), an inner collar portion ( 51 ) provided in the casing ( 50 ) and engaged with a groove portion ( 46 ) of the internal button ( 40 ), an overhanging portion ( 17 ) formed in the external button ( 10 ), and an outer collar portion ( 47 ) formed in the internal button ( 40 ) and located between the overhanging portion ( 17 ) and the inner collar portion ( 51 ) so as to define apart of the groove portion ( 46 ). The overhanging portion ( 17 ) is disposed separately from the outer collar portion ( 47 ) by a gap. The overhanging portion ( 17 ) abuts against the outer collar portion ( 47 ) when the external button ( 10 ) is pushed to elastically deform the internal button ( 40 ) to thereby turn on the switch ( 30 ).

TECHNICAL FIELD

The present invention relates to a push switch.

BACKGROUND ART

As a background-art push switch, there is a switch operation devicewhich is mounted in a vehicle in use and operated to be pushed from theoutside (Patent Document 1). As shown in FIG. 7, this switch operationdevice is provided with a switch 103 having a movable portion 102 andsoldered and fixed onto a circuit board 101, a casing 105 having anopening hole 104 and disposed in front of the switch 103, and a pushbutton 106 attached to the casing 105 at a circumferential edge of theopening hole 104 so as to close the opening hole 104.

This push button 106 is made from synthetic rubber with flexibility andhas an attachment portion 109 which is attached to the circumferentialedge of the opening hole 104, a pressing operation portion 110, a thinflexible portion 111 which connects the pressing operation portion 110with the attachment portion 109, and a shaft portion 112 which can movethe movable portion 102 of the switch 103 due to the pressing of thepressing operation portion 110. The push button 106 makes the inside ofthe casing 105 watertight. To operate this switch operation device, thepressing operation portion 110 of the push button 106 is pressed orreleased from pressing in the illustrated up/down direction so as toturn on/off the switch 103.

However, in the aforementioned push switch, because the push button ismade from a soft material, there is a fear that the push button may becracked or broken if the push button is hit by something hard such as anail when the push button is pushed by a finger or the like. Inaddition, the whole pressing force of an operator acts on the switchwhen the operator operates the push button of the push switch. Thus,there is a fear that the switch may be damaged if an excessive pressingforce is applied to the push button of the push switch.

Further, when the pushbutton of the push switch is operated, the pushbutton is not always pushed only from the illustrated up/down direction,but there is possibility that the push button may be pushed from anydirection. When, for example, the push button is pushed from anillustrated obliquely lateral direction, there is a fear that a lowerend of the shaft portion of the push button may move horizontally due toa certain way of the operator's pressing so that the pressing forcecannot be applied to the switch correctly.

PRIOR ART DOCUMENT Patent Document

-   Patent Document 1: JP-A-2009-009823

SUMMARY OF INVENTION

One or more embodiments of the invention provide a push switch which canprevent a pushbutton from being damaged even if the push button is hitby a nail or the like when the push button is operated, and which canprotect a switch even if an operating force with an excessive load isapplied.

In addition, one or more embodiments of the invention provide a pushswitch which can push a switch from any direction.

According to one or more embodiments of the invention, a push switch 1is provided with: a soft internal button 40 which includes a side wall43 and an upper wall 42 and has an opening portion 48 formed in a lowersurface thereof; an external button 10 which is formed of a hardmaterial, which includes a side circumferential wall 12 and an upperoperation wall 11, and which is fixed to the internal button 40 so as tocover the internal button 40; a switch substrate 20 which is disposed inthe opening portion 48 of the internal button 40; a switch 30 which isdisposed on the switch substrate 20 and inside the internal button 40; acasing 50 which is fixed to the side wall 43 of the internal button 40;a groove portion 46 which is formed in an outer circumference of theside wall 43 of the internal button 40; an inner collar portion 51 whichis provided in the casing 50 and engaged with the groove portion 46 ofthe internal button 40; an overhanging portion 17 which is formed in theexternal button 10 and which includes a substantially flat pressingsurface 18 provided in an end portion of the side circumferential wall12; and an outer collar portion 47 which is formed in the internalbutton 40 and which is located between the overhanging portion 17 andthe inner collar portion 51 and adjacently to the inner collar portion51 and defines a part of the groove portion 46. The overhanging portion17 is disposed oppositely to the inner collar portion 51. Theoverhanging portion 17 is disposed separately from the outer collarportion 47 by a gap. The overhanging portion 17 abuts against the outercollar portion 47 when the external button 10 is pushed to elasticallydeform the internal button 40 to thereby turn on the switch 30.

In the above structure, the inner collar portion 51 of the casing 50 maybe formed inward from an inner side of the casing 50 at least in aportion corresponding to the pressing surface 18 of the overhangingportion 17 of the external button 10.

In the above structure, a pressing portion 44 protruding both upward anddownward substantially at a center of the upper wall 42 of the internalbutton 40 may be provided integrally with the internal button 40. Anupper end surface of the pressing portion 44 may face the upperoperation wall 11 of the external button 10. A lower end surface of thepressing portion 44 may face an operation portion 31 of the switch 30.The lower end surface of the pressing portion 44 of the internal button40 may abut against an upper end surface of the operation portion 31 ofthe switch 30 even when a pressing force from an obliquely lateraldirection is applied to the external button 10.

According to the above structure, the external button which is hard isdisposed to cover the internal button which is soft. Thus, the internalbutton can be protected even if a nail or the like hits the externalbutton. In addition, even if an excessive pressing force is applied, theoverhanging portion of the external button abuts against the outercollar portion of the internal button when the external button is pushedby a stroke (corresponding to the gap between the overhanging portionand the outer collar portion) to turn on the switch. Thus, the pressingforce on the external button is received by the inner collar portion ofthe casing. It is therefore possible to provide a high-reliable pushswitch which can protect a switch without applying any excessivepressing force to the switch.

Other aspects and advantages of the invention will be apparent from thefollowing description and the appended claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an exploded perspective view of a push switch according to anexemplary embodiment of the invention.

FIG. 2 is a final perspective view of the push switch in FIG. 1.

FIG. 3( a) is a sectional view of the push switch in FIG. 2, taken online F-F. FIG. 3( b) is a sectional view of the push switch in FIG. 2,taken on line G-G.

FIG. 4 is a first operation sectional view of the push switch in FIG. 3(a).

FIG. 5 is a second operation sectional view of the push switch in FIG.3( a).

FIG. 6 is a modification of the push switch of the exemplary embodimentof the invention.

FIG. 7 is a sectional view of a background-art push switch.

DESCRIPTION OF EMBODIMENTS

An embodiment of the invention will be illustratively described belowwith reference to the drawings. Unless specific description is madeparticularly, there is no intention of limiting the scope of theinvention to materials, shapes, relative locations, etc. of constituentcomponents described in this embodiment.

FIG. 1 is an exploded perspective view of a push switch according to anexemplary embodiment of the invention. FIG. 2 is a final perspectiveview of the push switch in FIG. 1. FIG. 3( a) is a sectional view of thepush switch in FIG. 2, taken on line F-F. FIG. 3( b) is a sectional viewof the push switch in FIG. 2, taken on line G-G. FIG. 4 is a firstoperation sectional view of the push switch in FIG. 3( a). FIG. 5 is asecond operation sectional view of the push switch in FIG. 3( a).

In FIG. 1 to FIG. 3( b), a push switch 1 is attached to an opening holeof a not-shown door handle unit for a vehicle. An external button 10 ofthe push switch 1 is attached to the opening hole of the door handleunit so as to be exposed to the outside. When the external button 10 ispushed by a finger or the like, a door can be locked or unlocked.

The push switch 1 has the external button 10, a switch substrate 20, aswitch 30, an internal button 40, a casing 50 and a stopper 60.

The external button 10 is formed out of hard resin with rigidity, andhas a substantially quadrangular upper operation wall 11, asidecircumferential wall 12 which is provided erectly around the upperoperation wall 11, and two overhanging portions 17 which protrudeoutward from end portions of the side circumferential wall 12 parallelwith each other in the longitudinal direction of the push switch 1respectively, and which have substantially flat pressing surfaces 18respectively.

The internal button 40 is formed out of soft resin of silicone rubber.Not to say, the rigidity of the internal button 40 is lower than therigidity of the external button 10. In addition, the hardness of theinternal button 40 is lower than the hardness of the external button 10.The internal button 40 has a substantially quadrangular upper wall 42, aside wall 43 provided erectly around the upper wall 42, and an openingportion 48 formed in its lower surface. A groove portion 46 is providedall over an outer circumference of the side wall 43 of the internalbutton 40.

The insulating switch substrate 20 is mounted in a step portion 49inside the side wall 43 of the internal button 40. The stopper 60 islocked in the casing 50 from a lower surface of the switch substrate 20.

On the switch substrate 20, the switch 30 having an operation portion 31and a body portion 32 is disposed inside the internal button 40, so thata signal of the switch 30 can be transmitted to the outside throughconnection terminals 33A and 33B.

The operation portion 31 of the switch 30 is urged toward theillustrated upper side. When the operation portion 31 is pushed towardthe illustrated lower side, a sense of click is obtained and electriccontinuity is secured between not-shown contact points. When theoperation portion 31 is released from the pressing force, the operationportion 31 is restored to its original state so that electricdiscontinuity between the contact points is obtained. Thus, the switch30 can be turned on/off.

A substantially rectangular-parallelepiped pressing portion 44 whichprotrudes integrally in the illustrated up and down directions is formedsubstantially at the center of the upper wall 42 of the internal button40, as shown in FIGS. 3( a) and FIG. 3( b). (The pressing portion 44protrudes both upward and downward from the upper wall 42.) Opposite,upper and lower end surfaces of the pressing portion 44 are disposedclosely to or in contact with an inner wall of the upper operation wall11 of the external button 10 and an end surface of the operation portion31 of the switch 30 so as to be opposed thereto, respectively. The lowerend surface of the pressing portion 44 has a wider area than the endsurface of the operation portion 31 of the switch 30, so that the lowerend surface of the pressing portion 44 can always abut against all theend surface of the operation portion 31 of the switch 30 even if apressing force from an obliquely lateral direction is applied to theexternal button 10.

The casing 50 is formed out of hard resin and into a substantiallyquadrangular cylinder. The casing 50 has an inner collar portion 51engaged with the groove portion 46 around the side wall 43 of theinternal button 40. The inner collar portion 51 is formed to protrudeinward from an inner side of the casing 50 at least correspondingly tothe pressing surfaces 18 of the overhanging portions 17 of the externalbutton 10. The inner collar portion 51 may be provided inward from theinner side of the casing 50 and in the whole circumference of the casing50, so that water droplets can be prevented from entering the casing 50even if the water droplets adhere to a gap between the internal button40 and the casing 50. Mounting holes 53 for mounting the push switch 1on a door handle unit are provided outside the casing 50.

The aforementioned external button 10 is disposed to cover the outsideof the internal button 40 while securing a space B around the pressingportion 44, while holes 16 of the side circumferential wall 12 of theexternal button 10 are fitted to protrusion portions 45 of the side wall43 of the internal button 40 so as to fix the external button 10 to theinternal button 40. Thus, the internal button 40 can be protected evenif a nail or the like hits the external button 10 when the externalbutton 10 is operated and pushed.

As shown in FIG. 3( a), each overhanging portion 17 of the externalbutton 10 is disposed oppositely to the inner collar portion 51 of thecasing 50 and closely to an outer collar portion 47 through a gap A. Theouter collar portion 47 is provided between the overhanging portion 17and the inner collar portion 51 and adjacently to the inner collarportion 51 so as to form a part of the groove portion 46 of the internalbutton 40. The gap A between the overhanging portion 17 of the externalbutton 10 and the outer collar portion 47 of the internal button 40 ismade substantially equal to a stroke between a place where the externalbutton 10 is operated and pushed and a place where the pressing portion44 is elastically deformed to turn on the switch 30.

When the external button 10 is pushed from the illustrated upper sidetoward the illustrated lower side in the push switch 1 configured asdescribed above according to this embodiment, the external button 10 ispushed toward the illustrated lower side to elastically deform thepressing portion 44 of the internal button 40 as shown in FIG. 4, whilethe pressing portion 44 pushes the operation portion 31 downward to turnon the switch 30 (the state of FIG. 4).

On this occasion, an excessive pressing force maybe applied as anexternal force to the external button 10. Even in such a case, when theexternal button 10 is pushed correspondingly to the stroke of theexternal button (the gap A between each overhanging portion and theouter collar portion) to turn on the switch 30, the overhanging portions17 of the external button 10 abut against the outer collar portion 47 ofthe internal button 40 so that the pressing force of the external button10 can be received by the inner collar portion 51 of the casing 50.Thus, the switch can be protected without any excessive pressing forceapplied to the thereto.

When the pressing force is not applied to the external button 10anymore, the pressing portion 44 of the internal button 40 iselastically recovered so that the external button 10 and the operationportion 31 can return to their initial positions (the state of FIG. 3(a)). Thus, the switch 30 is disconnected. After that, cyclical operationcan be performed.

In this manner, according to the structure of the exemplary embodimentof the invention, the hard external button is disposed to cover the softinternal button so that the internal button can be protected even if anail or the like hits the external button. In addition, an excessivepressing force may be applied to the external button. Even in such acase, when the external button is pushed correspondingly to a stroke(the gap between each overhanging portion and the outer collar portion)to turn on the switch, the overhanging portions of the external buttonabut against the outer collar portion of the internal button so that thepressing force of the external button can be received by the innercollar portion of the casing. As a result, it is possible to provide ahigh-reliable push switch which can protect the switch without applyingany excessive pressing force to the switch.

In addition, the inner collar portion 51 of the casing 50 is formedinward from the inner side of the casing 50 at least in portionscorresponding to the pressing surfaces 18 of the overhanging portions 17of the external button 10. Thus, the overhanging portions 17 of theexternal button 10 abut against the inner collar portion 51 of thecasing 50 so that the pressing force of the external button 10 can bereceived by the inner collar portion 51 of the casing 50. As a result,it is possible to surely protect the switch without applying anyexcessive pressing force to the switch.

In addition, each overhanging portion 17 of the external button 10 isdisposed oppositely to the inner collar portion 51 of the casing 50 andseparately from the outer collar portion 47 by a gap. The outer collarportion 47 is provided between the overhanging portion 17 and the innercollar portion 51 and adjacently to the inner collar portion 51 so as toform a part of the groove portion 46 of the internal button 40. Thus,even when an excessive pressing force is applied to the external button10 suddenly, the overhanging portions 17 of the external button 10 abutagainst the soft outer collar portion 47 so that the pressing forceapplied to the inner collar portion 51 of the casing 50 can be relaxed.

In addition, the external button 10 is fixed to the outside of the softinternal button 40 so as to cover the internal button 40 while securinga space B around the pressing portion 44. Thus, a sense of clickgenerated when an operator operates and pushes the external button 10can be transmitted to the operator substantially without beingattenuated. The operator can confirm the switch operation surely.

In addition, a portion (the inner collar portion 51) for receiving anexcessive pressing force applied to the external button 10 is providedin the casing 50. Thus, it is not necessary to provide this receptionportion in the internal button 40. Accordingly, the space inside theinternal button 40 can be reduced so that the push switch can beminiaturized as a whole.

In addition, as shown in FIG. 5, the lower end surface of the pressingportion 44 of the internal button 40 abuts against the end surface ofthe operation portion 31 of the switch 30 even if a pressing force froman obliquely lateral direction is applied to the external button 10.Accordingly, even if the external button 10 is pushed from anydirection, the pressing portion 44 of the internal button 40 can beelastically deformed so that the pressing portion 44 can push theoperation portion 31 downward to turn on the switch 30 surely.

On this occasion, an excessive pressing force may be applied as anexternal force to the external button 10. Even in such a case, theoverhanging portions 17 of the external button 10 abut against the innercollar portion 51 of the casing 50 so that the external button 10 can bepushed correspondingly to a stroke (the gap A between each overhangingportion and the outer collar portion) to turn on the switch 30. Inaddition, the overhanging portions 17 of the external button 10 abutagainst the outer collar portion 47 so that the pressing force of theexternal button 10 can be received by the inner collar portion 51 of thecasing 50. As a result, it is possible to protect the switch withoutapplying any excessive pressing force to the switch.

When the pressing force is not applied to the external button 10anymore, the pressing portion 44 of the internal button 40 iselastically recovered so that the external button 10 and the operationportion 31 can return to their initial positions (the state of FIG. 3(a)). Thus, the switch 30 is disconnected. After that, cyclical operationcan be performed.

In the push switch 1 according to the aforementioned exemplaryembodiment, two overhanging portions 17 are provided in the externalbutton 10, and the inner collar portion 51 corresponding to theoverhanging portions 17 is provided in the casing 50. However, similareffect to the aforementioned effect can be obtained when fouroverhanging portions 17 are provided in corners of the substantiallyquadrangular upper operation wall of the external button 10 and theinner collar portion 51 corresponding to the overhanging portions 17 isprovided in the casing 50, as shown in FIG. 6.

As described above, the invention is not limited to the aforementionedembodiment, but it may be carried out with any suitable change withoutdeparting from the gist of the invention.

INDUSTRIAL APPLICABILITY

The invention is applicable to a push switch.

DESCRIPTION OF REFERENCE NUMERALS AND SIGNS

-   1 push switch-   10 external button-   11 upper operation wall-   12 side circumferential wall-   16 hole-   17 overhanging portion-   18 pressing surface-   20 switch substrate-   30 switch-   31 operation portion-   32 body portion-   33A connection terminal-   33B connection terminal-   40 internal button-   42 upper wall-   43 side wall-   44 pressing portion-   45 protrusion portion-   46 groove portion-   47 outer collar portion-   48 opening portion-   49 step portion-   50 casing-   51 inner collar portion-   53 mounting hole-   60 stopper-   101 circuit board-   102 movable portion-   103 switch-   104 opening hole-   105 casing-   106 push button-   109 attachment portion-   110 pressing operation portion-   111 flexible portion-   112 shaft portion-   A gap-   B gap

The invention claimed is:
 1. A push switch comprising: a soft internalbutton which includes a side wall and an upper wall and has an openingportion formed in a lower surface thereof; an external button which isformed of a hard material, which includes a side circumferential walland an upper operation wall, and which is fixed to the internal buttonso as to cover the internal button; a switch substrate which is disposedin the opening portion of the internal button; a switch which isdisposed on the switch substrate and inside the internal button; acasing which is fixed to the side wall of the internal button; a grooveportion which is formed in an outer circumference of the side wall ofthe internal button; an inner collar portion which is provided in thecasing and engaged with the groove portion of the internal button; anoverhanging portion which is formed in the external button and whichincludes a substantially flat pressing surface provided in an endportion of the side circumferential wall; and an outer collar portionwhich is formed in the internal button and which is located between theoverhanging portion and the inner collar portion and adjacently to theinner collar portion and defines a part of the groove portion, whereinthe overhanging portion is disposed oppositely to the inner collarportion, wherein the overhanging portion is disposed separately from theouter collar portion by a gap, and wherein the overhanging portion abutsagainst the outer collar portion when the external button is pushed toelastically deform the internal button to thereby turn on the switch. 2.The push switch according to claim 1, wherein the inner collar portionof the casing is formed inward from an inner side of the casing at leastin a portion corresponding to the pressing surface of the overhangingportion of the external button.
 3. The push switch according to claim 1,further comprising: a pressing portion which is provided integrally withthe internal button substantially at a center of the upper wall of theinternal button so as to protrude both upward and downward, wherein anupper end surface of the pressing portion faces the upper operation wallof the external button , and a lower end surface of the pressing portionfaces an operation portion of the switch, and wherein the lower endsurface of the pressing portion of the internal button abuts against anupper end surface of the operation portion of the switch even when apressing force from an obliquely lateral direction is applied to theexternal button.